Casing for electric meters



Filed July 22, 1925 Patented Mar. 26, 1929.

UNITED STATES PATENT OFFICE.

RENE MERCIER, OF PARIS, FRANCE, ASSIGNOR T0 COMPAGNIE CONTINENTALE POURLA FABRICATION DES GOMPTEURS & AUTRES APPAREILS, OE PARIS, FRANCE.

CASING ron ELECTRIC METERS.

Application filed July 22, 1925, Serial N02. 415,439, and in FranceNovember 7, 1924.

The casing for electric meters for subscribers, usually consists of ametallic envelope. Various metals such as iron, aluminium, zinc, brass,and the like, are employed for this purpose and said casings aremanufactured in the most economical manner by the casting process or bystamping in a single piece. In order to protect the meter against thedisturbing influence of the external fields, it has been the usualpractice to construct the said casings exclusively of cast iron or sheetiron. V

A very serious drawback whichis observed in'the use of such casingsconsists in the fact that it changes-the standardizing of the meterwhich is always regulated in the laboratory with the casing removed byreason of the magnetic shunting produced by the metal of the casing uponthe damping magnet which is always at a shortdistance therefrom.

The casing, the object of my invention allows of preserving theadvantages of the protection afforded by the magnetic casings eithercast or stamped in one piece, which can be made at a small cost, andalso of eliminating the difficulties in regulating which result fromtheir use. For this purpose the wall of the casing is formed in theregion near the magnet, of a non-magnetic metal such as copper, bronze,aluminium, etc., the said portion of the wall having suitable dimensionsin order that the magnetic part of the casing shall no longer af feetthe magnet.

In the accompanying drawings,

Figs. 1 and 2 are side views illustrating somewhat diagrammatically, twoembodiments of the present invention; and

Figs. 3 and 4 are detail sectional views illustrating two methods forsecuring a disk of nonmagnetic metal to the casing in accordance withthe present invention.

inserted a plate A of non-magnetic material,

which plate may be of a circular shape; the

purpose of said plate being to prevent the lines of force of the magnet(Fig. 3) being completed through the walls of said casing,

'which would occur if the casing were wholly of magnetic material. v

The shape of the said plate may be chosen as desired; it may even havethe shape of the front face of the said casing, 1. e. it may cover thewhole of the front face,-'as shown in Fig. 2 at B if the magnet 1ssituated at the front, or it may have any suitable disposition, whichmay be'favorable to the appearance of the apparatus.

The manner in which the plate is secured to the casing is optional; inparticular, the plate may consist of a piece which may be riveted orsoldered, or may be secured in place by means of a cast alloy, asillustrated in Fig. 3, or which may be secured in place by upsettingportions of the casing, as isshown in Fig. 4.

What I claim is 1 In an electric meter of the type described having adamping magnet, a casing of mag netic material for said meter, a coverof magnetic material for said casing and a metallic non-magnetic insertcarried by said cover in the portion thereof lying within the magneticfield of said damping magnet for the purpose disclosed.

In testimony whereof I have signed this specification.

MERCIER,

